


I Was Born to Tell You I Love You

by Ayanfe



Category: Shadowhunters (TV), The Mortal Instruments Series - Cassandra Clare
Genre: Family, Gen, Happy Ending, Isabelle Lightwood Deserves Nice Things, Little bit of angst, sibling feels
Language: English
Status: Completed
Published: 2017-03-15
Updated: 2017-03-15
Packaged: 2018-10-05 10:52:25
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,611
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10305371
Author URL: https://archiveofourown.org/users/Ayanfe/pseuds/Ayanfe
Summary: Isabelle has just turned sixteen when she asks Alec a question that breaks his heart.Isabelle is nineteen when Alec tells her something she didn't know she needed to hear.





	

**Author's Note:**

> Welcome to my writing, where we play it fast and loose with canon and have no idea when anything takes place. This is unbeta'd. Just a little something I wrote in the midst of my writer's block for a multi-chapter story I'm working on.

Isabelle has just turned sixteen when she asks Alec a question that breaks his heart.

They were just returning from a hunt. Alec reflects that it had been a good day. Isabelle didn’t try to cook breakfast, she and Jace listened to his advice, and no one was hurt. Perhaps coming home to see their mother marred it a bit. His mother has a sharp tongue.

Alec showered quickly and just finished getting dressed when Jace knocks. He asks if Alec is up to get lunch, then tells him to get Izzy and meet him downstairs when he agrees.

Alec pulls a Jace and knocks on Izzy’s door, opening it before he gets an answer. "Hey Izzy." He starts to ask her to settle the argument between Jace and himself - Korean barbecue versus Greek food - but forgets all about that when he sees his sister’s face.

"What’s wrong?"

Isabelle’s makeup is as flawless as ever. Long, fluttery lashes and perfectly outlined lips. She doesn’t even have a hair out of place from the fight with the Facemelter demons. But Alec knows his sister well enough to know that something is wrong. He sees it in the tightening of her mouth and hardened stare. Isabelle has always wielded her beauty like a weapon, but in that moment Alec thinks it might be armor. Isabelle never did like appearing weak.

"What do you mean, big brother?" And she’s good, he’ll give her that. Her voice is unwavering when she speaks. She even meets his eyes, but she holds his gaze a little too long, like she’s challenging him.

"Isabelle," he sighs, unsure of how to continue. He’s never been good with words - that was always Jace with his silver tongue, or Isabelle with her clever interrogations. He was too blunt, too tactless, the words clumsy in his mouth.

But he has no need to continue, because Isabelle blurts it out almost the moment her name leaves his lips.

"Do you think Mom still loves me?"

It takes Alec a minute to respond. Her question lights a fire in him. He is furious, livid, he wants to _hurt_ whoever put that exhaustion and confusion in his sister’s voice. But he can't do that, because it was their mother who did it.

Alec sits beside her on the bed and wraps her in a hug without thinking. Izzy relaxes, leans into him, and he’s glad that she occasionally lets him help her. "Isabelle, of course she does. You’re her daughter."

"Water of the womb," Isabelle murmurs into his shoulder. 

Alec isn’t angry, not anymore. Anger won’t help his sister. The worst part is that Alec understands why Isabelle might think the way she does. Maryse Lightwood is a hard woman to impress. He didn’t understand why she was harder on Isabelle, but he gets it. After a certain point, it’s exhausting to keep trying. What was the point of chasing something they could never catch?

Alec won’t lie to his sister. He can make all the reassurances he wants, he’s not the one she needs to hear them from. So he is honest where he can be. 

"It doesn’t matter," he tells her. "I love you. And so does Jace. We’ll love you enough for everyone." The words are cheesy and flowery, but they are genuine and that’s all he can offer. "And I’m ridiculously proud of you, Izzy."

Isabelle blushes, tries to brush off the praise. "Yeah, well, I suppose a basic understanding of biology does seem impressive when you don’t know the difference between DNA and RNA."

Alec refuses to let her. "I’m serious. You’re the smartest person I know, and even Jace admitted that you were probably a better Shadowhunter than him."

And as well as Alec knows Isabelle, she knows him just as much. She pulls back enough to look him in the eye, sees the stubborn glint he knows is there because he has seen it in Isabelle’s eyes so many times before, and realizes that this isn’t a fight she’s going to win.

Isabelle smiles and kisses him in the cheek. Judging from the twitch of her lips, he probably has a lipstick mark on his face, but he doesn’t try to wipe it off. "Thanks, Alec."

He doesn’t respond to that. There was no need to be thanked. "Come on, let’s go before Jace gets hungry enough to leave without us."

"Let’s be honest, he probably already did."

He didn’t. Jace is waiting for them by the front door of the Institute, and Alec isn’t sure if it’s the parabatai bond between them or the familial love between him and Izzy or his own perceptiveness, but Jace is well-aware of what’s going on.

Alec half-expects Jace to ignore the situation; he isn’t known for dealing with emotions well. Especially when they belong to someone else.

But Jace grins and hugs Isabelle like it’s been years since he last saw her, and he agrees easily when she suggests they get Thai. He spends the trip to the restaurant talking about the battle with the Facemelters.

"Seriously, Izzy, that was incredible! That move you did with that last one - with your whip and the seraph blade together. Thank Raziel we’re on the same team."

Isabelle laughs and says something teasing in response, and above her head Jace meets Alec’s eyes and nods.

_Thy people shall be my people._

 

* * *

 

Isabelle is nineteen when Alec tells her something she didn’t know she needed to hear.

It begins with Simon canceling on her. They made plans the night before, and at the last minute he calls with a mouthful of apologies, telling her that Raphael needs him for something. She tells him it’s fine, that they can reschedule, and hangs up. Then she gets unready, changes into a shirt she stole from Alec and her favorite cotton shorts, and falls asleep reading the biography of Abigail Shadowhunter.

Isabelle sleeps fitfully and when she wakes up for the fourth time at six in the morning, she groans and decides that trying to sleep is pointless.

She is ten pages back into the book when she slams it shut and tosses it on the floor. Isabelle realizes that she is angry and has no clue why.

No, she knows why. She is lonely. And stupid. She is stupid for loving people who all love someone else more. She’s annoyed that Simon ditched her last night when any other man would kill for a shot with her. She’s hurt that the memory demon they summoned so long ago proved what she suspected, and she’s jealous that her brothers are pathetically in love and - she takes a moment to admonish herself. These are ugly emotions she is feeling. She should be happy for her friends and family, and she _is_ \- she really is.

But that doesn’t mean it doesn’t hurt sometimes.

"Hey Izzy, you ready to train? Clary will be in the training room soon and we should go over the lesson plan."

Alec is standing in her doorway, all sweatpants and messy hair and a grin she assumes is Magnus-induced. Shit. She forgot that she agreed to help Alec teach Clary how to escape submission holds.

"Go away, Alec," she snaps. "We both know you can train Clary yourself." Isabelle knows right away that she messed up. If she wanted Alec to leave, she should have made up some excuse about being too tired or not feeling well. Alec isn’t the type to leave someone alone when they’re upset. Maybe that makes him dumb, maybe that makes him smarter than the rest of them.

Alec frowns and shuts her bedroom door before leaning back against it and folding his arms over his chest. "Okay. What did I do?"

"Nothing. Just go away." Isabelle winces when the words come out even harsher than before.

"Nope. I’m fine right here, but thanks for the concern." Alec’s stance changes, the way it does once someone realizes they are going to be standing in one spot for a while. Isabelle sighs. It seems she also forgot that Alec is a Lightwood, and their family can be annoyingly stubborn.

"Alec," she says, her tone softening. Too much, perhaps. Even to her own ears, she sounds sad. "I’m fine. Honestly. This has nothing to do with you." The lie doesn’t sound believable in the least, but she holds out hope that it will fool Alec.

For a moment she thinks it does, because Alec moves from his spot. Unfortunately, that hope is dashed when she sees Alec flop down sideways on her bed.

"Even better," he tells her, settling in. He steals one of her many pillows and shoves it under his head. "If it’s not about me then this should be easy."

"Seriously, _go away_." She yanks the pillow out from under him and hits him in the face with it.

"Ah." Alec nods solemnly. "So it is about me." He pauses, considers something, and sits upright. "If you’re mad at me, I really think you should tell me so I can fix it. But if you don’t feel like talking to me right now, I understand."

He looks to her for a response, so she says nothing.

"Okay, you aren’t talking to me. I’m not sure if this is one of those times where you say you want to be alone but actually don’t or what so…" Alec scans their surroundings and retrieves the pillow she took from him. "If you’re mad but want me to stay, hit me with this pillow. If you want me to go, just flip me off."

Isabelle rolls her eyes at her brother’s ridiculousness. She grabs the pillow back and tosses it aside, then punches him in the arm as hard as she can.

Alec flinches. "That was _not_ one of the options."

"It made me feel better."

"Did it?"

"No."

"Huh. If you want, you can burn some of my clothes. That usually makes Magnus feel better when he’s mad at me."

Isabelle recognizes the attempt to cheer her up, but all it does is remind her that she isn’t her brother’s priority, probably hasn’t been since Jace came along.

Alec squints at her. "Are you mad at Magnus?"

She scowls. "For God’s sake, Alec, leave it alone!"

"I wish I could, but when you were born I kind of took a blood oath to always protect you and try to make you happy and annoy you into telling me things."

Her lips twitch and she allows that Magnus Bane has been good for her brother. "No, you didn’t."

"How do you know?"

"Because you’re only two years older than me, idiot."

"Are you saying that toddlers can’t make blood oaths? Because let me remind you that I pledged part of my _soul_ to Jace when I was a teenager."

Again, it’s the wrong thing to say. Isabelle crosses her arms and tries to ignore Alec. Eventually he would get tired and leave. 

Alec sighs. "Okay, so you’re mad at me, Magnus, _and_ Jace. Should I just assume that Clary and Simon are on the list too?" She isn’t sure what, but something gives her away because Alec nods as if she gave him an affirmative. "Izzy, please talk to me. Or it doesn’t have to be me. But talk to Clary or Jace or Lydia or - hell, if you want, I can order Raj to come sit in here and let you yell at him."

It’s then that she decides to confide in her brother. It’s clear that he is worried, and she doubts he is going to leave any time soon.

"I’m sad. I think," she confesses. "I don’t know how to explain it - actually I _do_ , but it sounds terrible."

"Izzy, you could kill someone and I’d help you get rid of the body. There’s nothing so terrible you can’t tell me."

"…I’m mad that you love Jace more than me."

Alec’s eyes go wide.

She hurries to elaborate, to minimize the damage, but she makes it worse. "Not all the time. I accepted the fact that Jace is more important when you two became parabatai. Today is just a bad day. Simon ditched me for Raphael last night, and Clary spends most of her free time with Jace, and the memory demon picked Jace out of your memories and you’re always with Magnus, and I was never Mom’s favorite, but even Dad has been pulling away and I…" She takes a deep breath. "I’m just having a bad day."

Alec isn’t looking at her. He’s staring off into blank space when she finishes rambling.

"Alec?" Isabelle is worried that she said too much, that she made Alec feel guilty. 

"I didn’t know," he murmurs. He runs a hand through his hair, frustrated. "Fuck, I had no idea. How come I didn’t know?"

Isabelle is confused. She lets Alec mutter to himself for a few seconds more, tugging at his own hair and chewing on his lip.

"You know what I’ve learned from dating Magnus?"

She raises her eyebrows at the non-sequitur. "The extent of your gag reflex?" She jokes bitterly.

Alec doesn’t take the bait, doesn’t even roll his eyes at the comment. "That love isn’t always quantifiable. I don’t know how that memory demon worked exactly - it’s true that I love Jace, but Izzy, I don’t love him more than you."

Isabelle tilts her head the same way she does when she comes across a new concept in her studies that she doesn’t understand. "He’s your parabatai," she offers, certain that that sums up everything.

"And you’re my sister," Alec retorts fiercely. "I love all of you…I love Magnus - I love him beyond words, and I don’t know what I would do without him. Probably take up drinking." She isn’t sure if that’s a joke. "When Jace went missing, I went to pieces. You saw that. I was barely keeping it together. But fuck, Izzy, if you were gone, I’d be _catatonic_. I wouldn’t know how to function, I would-"

And then Isabelle is crying. Loud, ugly sobs. She stains Alec’s shirt - and it’s a nice one - with leftover eye makeup and tears and hell, probably snot. It’s definitely not her best moment, but the tight ball of guilt and sadness in her chest slowly unravels and by the time she’s done crying she doesn’t even know where it went.

Jace wanders in not long after, drawn to his parabatai, but Alec isn’t his first thought when he walks in. He makes a beeline for Isabelle, tousles her hair until she slaps his hand away and demands a Lightwood sibling group hug.

Then Clary comes in because shit, they missed her training session, but all she does is smile the way she always does, scrunched nose and bright eyes, and grabs a bottle of nail polish and Isabelle’s hand. She talks with Jace about her first fight with a bully when she was nine and banters with Alec like she’s known him for ages.

Isabelle is overwhelmed in the best way possible, and it nearly sets her off again, but then she catches Alec smiling. She leans more heavily against Jace, hoping she can catch a few more minutes of sleep before someone comes in to yell at them for not doing their jobs.

She wakes up nearly two hours later and sees her brothers and Clary all passed out, limbs tangled and bodies contorted in uncomfortable-looking positions, and it ends up being the ridiculousness of four people crammed together on her bed that sets her off. 

Isabelle wakes up the rest of them with her laughter.

**Author's Note:**

> Comment if you love the Lightwood siblings as much as I do.
> 
> Edit: Alright, time to do some blatant speculation and insert my own headcanons. It's canon that demons can't love, don't understand love. (See CoHF) And from my personal experience, I wouldn't be able to choose one single person that I love more than anybody. Valak (the memory demon) might have pulled the memories from who, in that moment, the group thought of when they thought of love. Think about it. Someone asks Clary who she loves the most - in the middle of a mission to rescue her mother? Of course Jocelyn is the first person she thinks of. For Alec, someone who has put forth so much effort keeping his love for Jace a secret and being ashamed of it, when he's confronted, told to think about who he loves the most - his first thought is Jace.
> 
> Make sense? Eh probably not. Oh well, this is fanfiction. Total hc that Simon's memory would have been of Clary. And shit, I almost cried when I saw that Izzy's memory was Alec smiling.


End file.
